1. Field of the Invention
The present invention relates to an overheat detection circuit configured to detect an abnormal temperature of a semiconductor device.
2. Description of the Related Art
A related-art overheat detection circuit is illustrated in FIG. 2. The related-art overheat detection circuit includes a reference voltage section 210, a temperature sensor 211, and a comparison section 212. The temperature sensor 211 includes a current source 202 and a PN junction element 203 for sensing temperature. The comparison section 212 includes a comparator 204. An output of the comparator 204 is connected to an output terminal Vout of the overheat detection circuit.
In the related-art overheat detection circuit, the comparator 204 compares and determines a voltage generated at the PN junction element 203, and a reference voltage Vref output from a reference voltage circuit 210, to thereby output an overheated state detection signal.
In general, the voltage generated at the PN junction element 203 exhibits negative temperature characteristics, and hence when an ambient temperature increases and the voltage generated at the PN junction element 203 falls below the reference voltage Vref, the comparator 204 outputs the overheated state detection signal to the output terminal Vout of the overheat detection circuit.
However, the above-mentioned overheat detection circuit suffers from a problem in that when disturbance noise, such as momentary fluctuations in the power supply, occurs, the comparator 204 may erroneously output the overheated state detection signal.